The present invention relates to backpacks and particularly to backpacks used in hiking and climbing. Within the field of hiking packs there is a distinction between packs used on long, relatively lowland type hikes, and packs used on mountain climbing expeditions. Many long hikes require large capacity packs that are capable of carrying food and supplies weighing in excess of 70 pounds. Large capacity packs in common use, today, generally are very tall and bulky packs. These packs are unsuitable for the relatively short climbs that hikers take upon arriving at the base of a mountain. The short mountain climbs do not require the hiker to carry all of his/her gear to reach the summit. It is much more convenient for a hiker to use a smaller pack that does not limit their movement while engaged in a technical climb of ice and/or rock.
Currently, hikers have few options in resolving the different backpack requirements on different stages of a hike. Some hikers carry a smaller backpack for technical climbs within their large capacity pack. this method requires the purchase of two separate packs and uses up extra space and weight within the large pack in carrying the small pack. Other hikers remove the exterior or interior frame from the shell of the large capacity pack and collapse the shell for use as a smaller pack. This method requires the painstaking steps of disassembling and reassembling the large pack. Furthermore, without a frame, the collapsed shell does not give the climber as much support for the load he/she is carrying within the shell. Finally, most hikers and climbers do not use either of the methods above, but instead, compromise by using a pack that is too large for comfortable climbing or is too small to carry a very heavy load on a hike of long duration.
The difference in use between hiking backpacks and climbing packs gives rise to an unresolved problem for the hiker. There are currently no backpacks available to the general public that resolve this problem of carrying two packs, or of needing two different frame lengths for a pack, and/or compromising on the size of the pack.